A CME, one type of "solar storm", erupts from the Sun in January 2002. The actual disc of the Sun, indicated by the white circle, is hidden in this view through an instrument called a coronagraph. The coronagraph creates an artificial eclipse by blocking the too-bright light from the Sun's surface, allowing us to view the Sun's dimmer atmosphere.
Click on image for full size
Images courtesy SOHO (NASA & ESA). Animation by Windows to the Universe staff (Randy Russell).

Coronal Mass Ejections

Have you ever seen an explosion before? Maybe you've seen a volcano explode on t.v. Or maybe you've seen a potato explode in the microwave because your mom forgot to poke holes in it. Well, explosions happen on the Sun too. We call these explosions coronal mass ejections or CME's. You can see a picture of a CME to the left!

Even though the Sun is very far away, these explosions on the Sun can affect things on Earth. Material that is thrown out from the Sun during a CME can disrupt radio communications or fry satellite electronics. This material can also cause strong geomagnetic storms, aurorae and power blackouts.

Because CME's affect Earth, we need to know when they are happening. Satellites like the ACE satellite act as a spaceweather station while in orbit. ACE can provide advance warning of any geomagnetic storms that would affect the Earth.

Last modified March 29, 2010 by Randy Russell.

You might also be interested in:

ACE Mission Page

Have you ever wondered what you are made of? Where did the elements come from that make up your body? The elements that make up your body are the same elements found on the Earth. Where did those Earth...more

Solar Storms

You know that there are all kinds of storms here on Earth - thunderstorms, blizzards, tornadoes, and hurricanes. The Sunalso has storms. There are two different kinds of storms on the Sun. They are called...more

ACE Satellite Probes Solar Event

Have you ever seen an explosion before? Maybe you've seen a volcano explode on t.v. Or maybe you've seen a potato explode in the microwave because you forgot to poke holes in it. Well, explosions happen...more

Comet NEAT passes Sun

The comet shown in this picture is really neat! It is so neat that scientists named it Comet NEAT! Actually, this comet was discovered by NASA's Near Earth Asteroid Tracking (NEAT) program, so that is...more

Massive Sunspot!

Right now, the largest sunspot of the decade is on the Sun. In this picture, it is the black smudge on the upper, right part of the Sun. Though it doesn't look like much, this area is more than the surface...more

Massive Sunspot! (Updated!)

There is a huge sunspot on the the Sun right now. It is the biggest in 10 years! It let off the largest solar flare and coronal mass ejection (CME) in ten years on Monday, April 2! This flare and CME...more

Yohkoh Mission

Have you seen a deep, red picture of the Sun like the one on this page? Do you know where it came from? The Yohkoh satellite may have taken it! Yohkoh was launched from Japan in 1991. For over ten years,...more

Solar Activity

The Sun is not a quiet place, but one that exhibits sudden releases of energy. One of the most frequently observed events are solar flares: sudden, localized, transient increases in brightness that occur...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA